Adrianichthys oophorus (Kottelat, 1990) Parenti, 2008

Parenti, Lynne R., 2008, A phylogenetic analysis and taxonomic revision of ricefishes, Oryzias and relatives (Beloniformes, Adrianichthyidae), Zoological Journal of the Linnean Society 154 (3), pp. 494-610 : 545-547

ADRIANICHTHYS OOPHORUS (KOTTELAT, 1990A) COMB. NOV.

EGGCARRYING BUNTINGI

FIGURES 8A , 10B , 18A , 24D , 29A , 33

Xenopoecilus oophorus Kottelat, 1990a: 59 , figs 5, 6 [type locality: Indonesia: Sulawesi, Lake Poso].- Soeroto & Tungka, 1991: 12–14 [listed, biology reproductive behaviour]- Uwa, 1991b: 15–18 [chromosomes, morphometrics].- Soeroto & Tungka, 1996: 22–26 [distribution, conservation status].- Seegers, 1997: 15, 18 [listed, photographs].- Parenti & Soeroto, 2004: 10–19 [comparisons, conservation status].- Springer & Johnson, 2004: 128–129, pl. 98 [gill arch morphology].

Differential diagnosis: Adrianichthys oophorus is distinguished from congeners by having fewer dorsal-fin rays (8–10 vs. 11–13 in A. poptae and 13–17 in A. kruyti and A. roseni ), fewer anal-fin rays (20–22 vs. 24–27), fewer pectoral-fin rays (12 vs. 13–16), a relatively small head (reaching 27% SL as opposed to reaching 32% or more) and short snout (reaching 9% SL, as opposed to 14% or more). Adrianichthys oophorus shares with A. poptae a single, rather than paired, subtriangular preethmoid cartilage, and ossified portions of mesethmoid semicircular anteriorly and subrectangular posteriorly (vs. disc-shaped). Adrianichthys oophorus shares with A. poptae and A. roseni an abdominal concavity between the pelvic fins and anal fin to carry developing embryos, and is most pronounced in A. oophorus .

Description: Large-bodied, maximum size of specimens examined 69.3 mm SL. Body elongate, slender, laterally compressed; body depth 16–18. Extremely pronounced abdominal concavity between pelvic fins and anal fin to carry developing embryos. Mouth terminal, upper and lower jaws subequal or lower jaw extending somewhat beyond upper jaw. Dorsal and ventral body profile relatively straight from head to dorsal and anal fin origin, dorsal body profile slightly convex posterior to head. Head length 25–27; snout length 8–9; eye moderate, 8–9, orbits project slightly beyond dorsal surface of head; articulation point of palatine and maxilla does not project beyond dorsal profile. Fleshy, incompletely scaly, basal portion of anal fin projects slightly beyond primary body profile. Scales small, cycloid and relatively deciduous; 58–65 in a lateral series. Anal-fin rays without contact organs. Relatively long, tubular urogenital papilla in some specimens. Medialmost pelvic-fin ray not connected to body via a membrane. Caudal fin lunate, dorsal and ventral segmented caudal-fin rays longer than middle rays.

Premaxilla flat and broad with no distinct articular or ascending processes; premaxilla and dentary with two irregular rows of small, villiform teeth; no enlarged, caniniform teeth on posterolateral ramus of premaxilla or dentary. Subtriangular preethmoid cartilage single; ossified portions of mesethmoid semicircular anteriorly and subrectangular posteriorly; anterior border of ethmoid cartilage straight. Palatine and quadrate articulate via elongate flanges that overlap anteriorly. Dorsal ramus of hyomandibula bifid, with separate cartilages that articulate with sphenotic and pterotic. Lacrimal sensory canal carried in open bony groove. First pleural rib on parapophysis of third vertebra; lateral process of pelvic bone attaches to sixth pleural rib. Caudal skeleton with two epural bones; one relatively straight, ventral accessory bone. Fifth ceratobranchial toothplates subtriangular, with pavement dentition anteriorly followed posteriorly by four or five tooth rows; no small, incomplete posterior row. Basihyal bone elongate and triangular; basihyal cartilage rectangular. Epibranchial elements fully ossified; epibranchial 2 with a broad point of articulation with ceratobranchial cartilage.

Dorsal-fin rays 8–10. Anal-fin rays 20–22. Pelvic-fin rays 6. Pectoral-fin rays 12. Principal caudal-fin rays i,5/6,i. Procurrent fin-rays, dorsal 7, ventral 7. Vertebrae 36 (15 + 21). Branchiostegal rays 5–6.

Cytogenetic data: A metaphase chromosome figure of A. oophorus published by Uwa (1991b: fig. 3) demonstrates what appears to be 40 pairs of chromosomes. The preparation was considered inadequate for an accurate characterization of karyotype.

Colour in life: Body translucent and fins hyaline; melanophore pattern as described below in alcohol.

Colour in alcohol: Ground colour greyish brown dorsally with ventral surface of body and caudal peduncle white. Dark brown to black chromatophores concentrated on dorsal surface of head and along middorsal surface of body to caudal fin. A thin, black midlateral stripe, with scattered melanophores above and below, from the head to the caudal peduncle. Fins hyaline.

Distribution and habitat: A pelagic species endemic to Lake Poso, Sulawesi Tengah ( Parenti & Soeroto, 2004: fig. 1). Hundreds of specimens, both large adults and juveniles, were collected at night in open waters of Lake Poso during a 1995 expedition. Individuals were attracted to a boat using kerosene lamps and then collected using dip nets. Many individuals, in addition to those listed below, were seen but not taken.

Remarks: The largest specimen of A. oophorus examined by Kottelat (1990a: fig. 6, ZSM/CMK 6240, 65.1 mm, paratype) has an embryo cluster held in an abdominal concavity between the body and the pelvic fins. The observations of spawning in December to January ( Soeroto & Tungka, 1991), June ( Kottelat, 1990a) and August (specimens reported below) suggest that A. oophorus spawns year-round. Data were augmented by those in Kottelat (1990a). The holotype (ZSM/LIPI 5, 37.2 mm SL) was not examined by me. Another common name for this species is egg carrying poso minnow ( Seegers, 1997: 18).

Material examined: 1335 specimens (8.0– 69.3 mm SL).

Paratypes. INDONESIA. Sulawesi Tengah: Lake Poso , east shore between Tentena and Peura, ZSM/ LIPI 6 , 5 (21.1–35.8 mm), ZSM/CMK 6360 (formerly CMK 6236 ), 1 (27.5 mm, cleared and counterstained), M. Kottelat, 23–25.ix.1988 .

Non-type specimens. INDONESIA. Sulawesi Tengah: Lake Poso, west bank of Poso R. where it empties into lake at Pamona Caves , USNM 340431 , 633 (9.2– 69.3 mm), L. R. Parenti, K. D. Louie, P. Beta & Young, 11 Aug 1995 , USNM 350469 , 335 (9–66.3 mm, 5 of which have been cleared and counterstained), L. R. Parenti, K. D. Louie, P. Beta & boatmen, 13.viii.1995 . Lake Poso , eastern shore approx. 17 km S of Tentena, USNM 348386 , 93 (8.6–66.8 mm, 6 of which have been cleared and counterstained), USNM 348724 , 268 (8–59.1 mm), L. R. Parenti, K. D. Louie, P. Beta et al., 12.viii.1995 .

ADRIANICHTHYS POPTAE ( WEBER & DE BEAUFORT,

Figures

Figure 8. A, Adrianichthys oophorus, USNM 350469, subadult, 41 mm SL; B, Oryzias bonneorum, ZMA 123.863, adult female, 40 mm SL. Diagrammatic representation of jaws and jaw suspensorium drawn to same scale. Dashed line approximates outline of Meckel’s cartilage. Anterior is to the left.

Figure 10. A, Dermogenys robertsi, CAS 137635, 39 mm SL; B, Adrianichthys oophorus, USNM 350469, 41 mm SL. Diagrammatic representation of the left shoulder girdle. Anterior is to the left. Scale bar = 1 mm.

Figure 18. A. Adrianichthys oophorus, USNM 348386, female, 60 mm SL; B. A. roseni, USNM 322425, female, 73 mm SL. Anterior portion of skull, jaws and jaw suspensorium. The cartilage that may be seen between the two preethmoid cartilages in B is the cartilaginous symphysis of the dentaries. Anterior is up.

Figure 24. A, Hemirhamphodon kuekenthali, USNM 330828, adult male, 50 mm SL; B, Adrianichthys roseni, USNM 322425, adult female, 73 mm SL; C, Adrianichthys poptae, USNM 322423, adult female, 168 mm SL; D, Adrianichthys oophorus, USNM 348386, female, 60 mm SL; E, Oryzias bonneorum, ZMA 123.863, adult female, 40 mm SL; F, Oryzias dancena, USNM 342156, adult male, 24.5 mm SL. Diagrammatic representation of the hyoid bar. Arrows indicate posterior extent of the ramus of the ventral hypohyal. Beloniform fishes lack an interhyal. All drawn to same scale.

Figure 29. A, Adrianichthys oophorus, USNM 348386, 60 mm SL. B, Oryzias orthognathus, USNM 350562, 43.5 mm SL. Caudal fin osteology. Arrows point to anteriormost dorsal and ventral procurrent rays. Note hooked proximal portion of the procurrent rays in B.

Figure 33. Adrianichthys oophorus (Kottelat, 1990a), Lake Poso, Sulawesi Tengah, Indonesia, USNM 340431, female, 58 mm SL, carrying cluster of embryos.